N,n&#39;-bis(4-benzilyl-substituted)tetracarboxylic imides

ABSTRACT

PHENYLATED IMIDE QUINOXALINE CO-POLYMERS CONSISTING ESSENTIALLY OF UNITS OF THE FORMULA   (-CH2-CO-N(-R(-))-CO-CH2-)&gt;Y&lt;(-CH2-CO-N(-R-(3-C6H5-QUIN-   OXALIN-2,7-YLENE)-X-(3-C6H5-QUINOXALIN-7,2-YLENE)(-))-   CO-CH2-)   WHEREIN X IS A DIRECT BOND, O, S, SO SO2 OR   -CO-   R IS M- OR P-PHENYLENE AND Y IS   1-((3,4-DI(-)PHENYL)-CO-),3,4-DI(-)BENZENE, OR 2,3,4,5-   TETRA(-)TETRAHYDROFURAN   WHICH ARE USEFUL AS COATINGS FOR FIBERS, GRAPHITE PRECURSORS, FILMS AND LAMINATING MATERIALS ARE PREPARED BY CONTACTING   1-((3,4-DI(NH2-)PHENYL)-CO-),3,4-DI(NH2-)BENZENE   WITH   (-CH2-CO-N(-(1,4-PHENYLENE)-CO-CO-C6H5)-CO-CH2-)&gt;Y&lt;(-CH2-   CO-N(-(1,4-PHENYLENE)-CO-CO-C6H5)-CO-CH2-), OR (-CH2-CO-   N(-(1,2-PHENYLENE)-CO-CO-C6H5)-CO-CH2-)&gt;Y&lt;(-CH2-CO-N(-   (1,2-PHENYLENE)-CO-CO-C6H5)-CO-CH2-)

United States Patent Oi'fice 3,726,899 Patented Apr. 10, 1973 This is adivision of application Ser. No. 128,524, filed 3,726,899 Mar. 26, 1971,now US. Pat. No. 3,654,226.

N,N'-BIS(4-BENZILYL-SUBSTITUTED) TETRACARBOXYLIC IMIDES Joseph M. Augl,Sterling, Va., and James V. Duffy, Beltsville, Md., assignors to theUnited States of America as represented by the Secretary of the Navy NoDrawing. Original application Mar. 26, 1971, Ser. No. 128,524, nowPatent No. 3,654,226. Divided and this BACKGROUND OF THE INVENTION Thisinvention relates generally to polymers and more particularly tophenylated imide-quinoxaline copolymers. Phenylated polyquinoxalines areknown and have been disclosed in copending application Ser. No. 876,572,filed application Nov. 16, 1971, Ser. No. 199,354

Int. Cl. C07d 27/52 US. Cl. 260-326 N 3 Claims ABSTRACT OF THEDISCLOSURE Phenylated imide quinoxaline co-polymers consistingessentially of units of the formula wherein X is a direct bond, 0, S, S0S0,, or

some of these polymers, even those with a relatively high molecularweight, are very soluble in common organic solvents. Since thesepolymers can be used as coatings, it is highly desirable that they beeasily removed by contacting with common organic solvents so that it ispossible to easily inspect or repair materials which have been coatedwith them. Furthermore, polymer coatings of the prior art often have tobe heat cured before they can be used thereby requiring an additionalstep in order to use them effectively. A continuing search goes on forpolymers which do not require a heat cure, which can be used as coatingsand which have good oxidative-thermal stability as well as goodsolubility in common organic 4o solvents.

R is mor p-phenylene and Y is the or U which are useful as coatings forfibers, graphite precursors, films and laminating materials are preparedby contacting HlN X NH, SUMMARY OF THE INVENTION HIN N fl Accordingly,one object of this invention is to provide phenylated imide-quinoxalinecopolymers.

Another object of this invention is to provide phenylatedimide-quinoxaline copolymers which have excellent oxidative-thermalstability.

A still further object of the instant invention is to provide phenylatedimide-quinoxaline copolymers which can he used as high temperatureprotective coatings for fibers, graphite precursors, films andlaminating materials.

Yet another object of the present invention is to provide a phenylatedimide-quinoxaline copolymer which requires no heat cure before usebecause of imide ring 0 formation prior to polymerization. 55 A furtherobject of this invention is to provide starting materials from which thephenylated imide-quinoxaline copolymers of this invention can beprepared.

These and other objects of this invention are accomplished byprovidingcopolymers consisting essentially of units of the formula with G N ML 1wherein X is selected from the group consisting of a direct bond, 0, S,S0, S0,, and

R is selected from the group consisting of mand p-phenylene and Y isselected from the group consisting of which are prepared by contactingHzN 9 NH: H2N X 6 NH:

g III 0 O at when R is p-phenylene and with when R is m-phenylene.

DESCRIPTION OF THE PREFERRED EMBODIMENT The phenylated imide-quinoxalinecopolymers of this invention are prepared by reacting compounds ofFormula II with compounds of Formula 111 when R is to be p-phenylene andwith compounds of Formula IV when R is to be m-phenylene. The reactionsequence that is used to prepare compounds of Formula III is depicted asfollows:

When compounds of Formula IV are desired the reaction sequence isidentical except that is the initial starting material. The first stepin the sequence is the reduction of the nitro group to the amino groupby any of the conventional reduction techniques, such as, for example,treatment with iron in an acid solu tion, to obtain V. The aminocompound obtained is then acylated by reaction with acetic anhydride inthe conventional manner to obtain VI. Once acylated the compound istreated with selenium dioxide to oxidize the methylene group to acarbonyl to obtain VII. To form the amino analogue VIII, VII is treatedwith an acid. VIII is then converted to III by reaction with a compoundof Formula IX.

The polymer is prepared by reacting in a solvent, such as m-cresol, thetetraamine of Formula II with the compounds of Formula III or IV. Thisreaction may be conducted entirely at room temperature or at a somewhatelevated temperature. It is desirable, though not necessary, to raisethe temperature to above C. for a few minutes at the end of the reactionin order to drive out the water that has formed during the reaction.

The general nature of the invention having been set forth, the followingexamples are presented as specific illustrations thereof. It will beunderstood that the invention is not limited to these specific examplesbut is susceptible to various modifications that will be recognized byone of ordinary skill in the art.

EXAMPLE 1 4'-aminodeoxybenzoiu A mixture of 64.0 g. of4-nitrodeoxybenzoin, 40.0 g. of iron powder, 3.5 ml. of concentratedhydrochloric acid, 500 ml. of ethanol, and 250 ml. of Water was refluxedfor one hour. The hot solution was filtered and the filtrate was pouredinto 1.5 liters of water, giving a slight yellow precipitate, M.P. 95-7C.

EXAMPLE 2 4'-acetamidodeoxybenzoin A mixture of 20.0 g. of4'-aminodeoxybenzoin, 50 ml. of glacial acetic acid, and 50 ml. ofacetic anhydride was heated at reflux for two hours. The solution wasthen poured into one liter of water, giving a white solid which wasrecrystallized from a mixture of ethanol-water (1:1), M.P. 158-160 C.

EXAMPLE 3 4-acetamidobenzil A mixture of 18.0 g. of4'-acetamidodeoxybenzoin, 8.5 g. of selenium dioxide, and 200 ml. ofglacial acetic acid was heated at reflux for two hours and thenfiltered. Then the mixture was poured into one liter of water. The yieldof 4-acetamidobenzil monohydrate was 20.0 g. After tworecrystallizations from benzene, the solid was dehydrated, M.P. 136-8 C.

EXAMPLE 4 4-aminobenzil A mixture of 4-acetamidobenzil (15.0 g.) and ml.of concentrated hydrochloric acid was refluxed for four hours. The solidwas filtered and made basic with sodium hydroxide to obtain the freebase. The precipitated solid 6 was recrystallized from ethanol-water(1:1) to give 12.1 nitrogen for 16 hours at room temperature. A total ofg. of 4-aminobenzil, a pale yellow solid, M.P. 127-9 C. 8 ml. of aceticanhydride and 2 ml. of pyridine were then EXAMPLE added and thetemperature was maintained at 80 C. for a period of 4 hours. Aftercooling, the solution wasN,N'-bis(4-benzilyl)-3,3',4,4'-benzophenonepoured into 400 ml. of waterto give a bright lemon yellow tetracarboxylimide 5 colored solid. Yield2.0 g., M.P. 279- C.

A mixture of 4-aminobenzil, 2.87 g. of3,3,4,4'-benzophenonetetracarboxylic dianhydride and 50 ml. of di-EXAMPLE 7 methylacetamide was stirred under nitrogen for 16 hours atroom temperature. At this point, 8 ml. of acetic an All the polymers ofthis invention listed in the followhydride and 2 ml. of pyridine wereadded, and the mix- 25 ing table were prepared in the same manner.Equimolar ture was then refluxed for 8 hours. After the first 5 amountsof the app p constituents, Preferably about hours of reflux, 2 ml. moreof pyridine were add d, A 0.001 mole of each, were stirred undernitrogen in mlight yellow solid precipitated which was filtered dcresol. In all cases a 10% by weight solution was used. washed with a1:1 mixture of hexane-acetone. The yield The temperature Was p betweenC. for ffOm was 4.0, g., M.P. 2801 C. 30 2 to 3 hours. In actualpragtice the reaction is almost complete in about A hour ut it is bestto heat for a EXAMPLE 6 longer period of time to affect completeconversion. Dur- N,N-bis(4-benzilyl)tetrahydrofurantetracarboxylamideing the last 15 minutes the temperature was raised to O II A mixture of4.0 g. of 4-aminobenzil, 1.89 g. of tetrareflux. The characteristics ofsome of the polymers prehydrofurantetracarboxylic dianhydride wasstirred under pared in this manner are given in the table.

Polymer b decompo- Polymer 01' Formula I wherein X, R, and Y are-Inherent sition viscosity, tempera- X R Y d1./g ture, C.

1 Direct bond... p-Phenylene. 1.54 530 2 ..d0 Same as above 0. 78 525 3S0 -d0 do 0.62 490 4 0 do ..d0 1.09 515 5 Direct bond do l l 2.07 290 06 *fldo Sameasabove. 1.02 310 Determined as a 0.5 g. in 100 ml. m-cresolsolution at 30 C. b Determined from TGA data in vacuum at a heating rateof 6 0. per minute.

The polymers of this invention have an inherent viscosity of betweenabout 0.4 and 3.0 dL/g. in m-cresol (0.5 g. in 100 ml. at 30 C.). Forlaminate coatings a viscosity of between about 0.4-0.9 is preferredwhile for films and fibers a viscosity as high as possible is preferred.To obtain the relatively high viscosities, it is only necessary to usevery pure materials. These copolymers are also relatively soluble insolvents such as mcresol, m-methoxyphenol, tetrachloroethane,chloroform, dimethylacetamide, N-methylpyrrolidone, hexafluoroacetone,hexafluoroisopropanol, nitrobenzene, and pyridine.

Obviously, numerous modifications and variations of the presentinvention are possible in light of the above teachings. It is thereforeto be understood that within the scope of the appended claims theinvention may be practiced otherwise than as specifically describedherein.

What is claimed as new and desired to be secured by Letters Patent ofthe United States is:

1. A compound of the formula wherein R is selected from the groupconsisting of m and p-phenylene and Y is selected from the group con- 2.A compound according to claim 1 wherein R is p-phenylene and Y is 3. Acompound according to claim 1 wherein R is pphenylene and Y isReferences Cited UNITED STATES PATENTS 3,275,651 9/1966 Ellis et al.260326 N JOSEPH A. NARCAVAGE, Primary Examiner US. Cl. X.R. 260-3263

